Increasing numbers of persons with significant physical disability since birth, childhood, or early adult years are aging into late middle and old age. Persons aging with physical disability ? defined here as impaired motor functioning and limitations in movement activities ? face increased risks of developing secondary conditions related to their underlying disability. They also frequently develop comorbidities, conditions that arise independently of the disabling condition, such as cancer. Even with significant physical disability, comorbid conditions like cancer require treatment to extend longevity and improve quality of life, although competing personal and health priorities may affect diagnostic and therapeutic choices. This exploratory and developmental project will examine whether ?diagnostic overshadowing? relating to significant physical disability might delay the diagnosis of cancer, a potentially life-threatening comorbid health condition. The phrase diagnostic overshadowing was first used to describe the misattribution of symptoms of serious mental illness to persons' intellectual disability (ID) among individuals with ID; it is now often applied in the context of serious mental illness to the erroneous attribution of physical health symptoms to a patient's mental illness. No one has yet examined whether diagnostic overshadowing might cause delayed cancer diagnoses among persons with physical disability, with cancer symptoms patients report being incorrectly attributed to their underlying disabling condition. This R21 project will have three specific aims: 1. To examine the population prevalence of cancer diagnoses among civilian, noninstitutionalized adults with physical disability by cancer type and disability severity. Using National Health Interview Survey data, this aim will delineate the potential scope of the problem and identify 4 specific cancers for in-depth exploration. 2. To explore patterns of diagnostic evaluations for 4 common cancers among adults with pre-existing significant physical disability compared with patterns among adults with insulin-dependent diabetes without physical disability. Using the Research Patient Data Registry (RPDR), a rich clinical database, this aim will examine the types and timing of clinician visits and diagnostic tests pre-cancer diagnosis for persons with and without physical disability, matched by age, sex, cancer type and stage, and year of diagnosis. 3. To explore perceptions of individuals with pre-existing physical disability who subsequently develop one of the 4 selected cancers about the possible effects of their physical disability and other factors on their diagnostic process, timing, and experiences. Using an open-ended protocol to interview 20 individuals randomly chosen from the RPDR Aim 2 analyses, we shall apply descriptive qualitative methods to generate hypotheses about disability factors related to the nature and timing of the cancer diagnostic process and develop initial recommendations for improving timeliness of cancer diagnoses. This proposal is submitted in response to PA-17-259, which calls for projects at ?early and conceptual? stages.